Corliss Steam Engine (Coles Power Models)

[ZAPJACK]

and the finished connecting rod.

 

[ZAPJACK]

Désolé, je suis un peu en retard dans mes publications.
Il s'agit du roulement de bielle fini avec l'écrou de blocage.

Montage vierge UN

Centrage avec le centrifugeur Deckel

Dispositif de graissage sans graisseur et vis provisoire

Dernière difficulté avant le montage, les quatre valves.
J'ai un peu peur de l'usiner. Fraises larges 1/16", 7°, tolérance d'usinage, Etc..
LZ

 

[DaveR]

Your engine is looking great! I'm building the same engine and cringed at the thought of milling the 1/16" wide slot 1/4" deep in the steam valves, so I cheated and drilled a series of 1/16" holes as close together as possible. I think this will allow plenty of steam throughput; time will tell!

Dave

 

[Richard Hed]

Your engine is looking great! I'm building the same engine and cringed at the thought of milling the 1/16" wide slot 1/4" deep in the steam valves, so I cheated and drilled a series of 1/16" holes as close together as possible. I think this will allow plenty of steam throughput; time will tell!

Dave

Do you have a photo? Am not exactly sure what you mean.

 

[DaveR]

Do you have a photo? Am not exactly sure what you mean.

Richard,

Here's an exhaust valve (with through slot) and a steam valve (with 1/16" holes). I forgot that I milled a 1/16" wide slot about 1/16" deep to match up with the slot in the cylinder, hoping this would leave the valve timing unaffected by he use of holes in place of a slot all the way through.

Dave

 

[Richard Hed]

Richard,

Here's an exhaust valve (with through slot) and a steam valve (with 1/16" holes). I forgot that I milled a 1/16" wide slot about 1/16" deep to match up with the slot in the cylinder, hoping this would leave the valve timing unaffected by he use of holes in place of a slot all the way through.

Dave

View attachment 154046

Dave,
I too am working on this Corliss. I'm wondering why you have put 1/16th " slots for the valve stem on both ends. This might cause friction when running. Also, am curious if that exhaust valve has a slot the length of the valve? It llooks like it but might just be the photo. What about the side with the slanted section? What is that called anyway? That part, especially on the exhaust will be verhy difficul;t for me to do. However, I managed to get some extra CI incase I blow one or two.

 

[DaveR]

Dave,
I too am working on this Corliss. I'm wondering why you have put 1/16th " slots for the valve stem on both ends. This might cause friction when running. Also, am curious if that exhaust valve has a slot the length of the valve? It llooks like it but might just be the photo. What about the side with the slanted section? What is that called anyway? That part, especially on the exhaust will be verhy difficul;t for me to do. However, I managed to get some extra CI incase I blow one or two.

Richard,

I'll admit, these things were a pain the neck. Of course, the "slots" I was referring to in my earlier post were for the passage of steam (and exhaust). As for the slots on the ends of the valves, one end is to drive the valve. The slot on the other end is in the drawings and is, I believe, used for assembly and/or timing purposes; it does nothing once everything is assembled and running.

I was able to but the slot all the way through the exhaust valve because this one is 1/8" wide, so not to unreasonably thin. Oh, and I should say, I did trash one steam valve when I was almost finished with it. Argh!!!

Dave

 

[Richard Hed]

Richard,

I'll admit, these things were a pain the neck. Of course, the "slots" I was referring to in my earlier post were for the passage of steam (and exhaust). As for the slots on the ends of the valves, one end is to drive the valve. The slot on the other end is in the drawings and is, I believe, used for assembly and/or timing purposes; it does nothing once everything is assembled and running.

I was able to but the slot all the way through the exhaust valve because this one is 1/8" wide, so not to unreasonably thin. Oh, and I should say, I did trash one steam valve when I was almost finished with it. Argh!!!

Dave

LOL, yeah, that's why I found some extra CI. Yes, I thimpfks I saw a drawing like that with the slots on both ends but I don't have them on mine (me thimpfks).

Do you have a rotary table? That would make cutting those bevels on the valves a WHOLE lot easier. Am not sure how I'm going to do it, don't have a rotary. Am working slowly on building a rotary but so far . . . .

Anyway keep us up[ on your work with lots oif photos.

 

[DaveR]

LOL, yeah, that's why I found some extra CI. Yes, I thimpfks I saw a drawing like that with the slots on both ends but I don't have them on mine (me thimpfks).

Do you have a rotary table? That would make cutting those bevels on the valves a WHOLE lot easier. Am not sure how I'm going to do it, don't have a rotary. Am working slowly on building a rotary but so far . . . .

Anyway keep us up[ on your work with lots oif photos.

I used a 5c spin indexer (for example: https://www.grizzly.com/products/grizzly-5-c-spin-index/g5649). I prepared a rod long enough to make two valves, plus a bit extra in the middle, say an extra 1", so I could hold one end in the indexer while machining the other end. The two valves were separated from the rod after the other machining was complete.

By the way, these indexers are super handy for lots of things. Think hex heads for model bolts, etc, etc. Of course, you'll need 5c collets to use it.

I should post some photos of my build but I don't want to hijack this tread.

Dave

 

[plipoma]

Your engine is looking great! I'm building the same engine and cringed at the thought of milling the 1/16" wide slot 1/4" deep in the steam valves, so I cheated and drilled a series of 1/16" holes as close together as possible. I think this will allow plenty of steam throughput; time will tell!

Dave

Dave, I used a 1/16" wide, small diameter slitting saw in the mill and finished the ends with a jewelers file.

 

[Richard Hed]

Dave, I used a 1/16" wide, small diameter slitting saw in the mill and finished the ends with a jewelers file.

did you use the slitting saw to cut out the bevels?

 

[plipoma]

did you use the slitting saw to cut out the bevels?

The valve was not trimmed to length and in a spin index. Don’t remember for sure but think I used an end mill. I’ll try and find pictures.

 

[plipoma]

The valve was not trimmed to length and in a spin index. Don’t remember for sure but think I used an end mill. I’ll try and find pictures.

Attached is photo of slitting saw operation and it looks like I used end mill for bevels, this was 4 years ago and my memory isn't serving me well. The third photo shows finished valves, note I cut a small groove in each end to serve as an air seal for blow by.

 

[Richard Hed]

Attached is photo of slitting saw operation and it looks like I used end mill for bevels, this was 4 years ago and my memory isn't serving me well. The third photo shows finished valves, note I cut a small groove in each end to serve as an air seal for blow by.

THAT is FERY een-tehr-resteenk! What a very clever method. However, I'm curious why you built in a "blow by" groove. Won't that cause leakage?

Are those CI? They look more like steel.

 

[plipoma]

THAT is FERY een-tehr-resteenk! What a very clever method. However, I'm curious why you built in a "blow by" groove. Won't that cause leakage?

Are those CI? They look more like steel.

The blow by groove actually improves sealing. Any flow causes a turbulence, which acts somewhat as an air seal.
I used 12L14 precision stock from McMaster Carr.

 

[Richard Hed]

The blow by groove actually improves sealing. Any flow causes a turbulence, which acts somewhat as an air seal.
I used 12L14 precision stock from McMaster Carr.

I understand the theory, but it is rather difficult for me to visualize.

 

[ZAPJACK]

Richard,

Voici une soupape d'échappement (avec fente traversante) et une soupape de vapeur (avec des trous de 1/16"). J'ai oublié que j'ai fraisé une fente de 1/16" de large et d'environ 1/16" de profondeur pour correspondre à la fente du cylindre, en espérant que cela laisserait le calage des soupapes inchangé par l'utilisation de trous à la place d'une fente tout au long.

Dave

View attachment 154046

bonne idée !, je vais suivre ta suggestion, mais en terminant avec une fraise en bout
LeZap

 

[Richard Hed]

bonne idée !, je vais suivre ta suggestion, mais en terminant avec une fraise en bout
LeZap

Well, Look at that, it proves the French do not have a word for "entrepreneur".

 

[ZAPJACK]

Two misfired valves!
The first difficulty is that the bores are different, by a few hundredths but still. Then the bore has a taper of 0.02mm by 50mm, this is unacceptable but real!
Machining valves with -0.01mm clearance and taper is not a big problem.
The first one, I missed because I was wrong in the dimensions on Y
The second, I centered the spindle in X and Y but milling at 1/16" or 1.50mm, the milling being 1.85mm real
In fact, I should be running at 5600rpm but my Schaublin cannot run above 2000rpm. and the advance too fast.
For the third test, I will take a saw cutter of 1mm and 20mm in diameter and "open" the slot then finish with the end mill, at maximum speed and minimum advance. It's from his bullshit that we learn!. In the meantime, I paint! LZ

 

[ZAPJACK]

Waiting for ordered tools, I start again.
The first two images are tests to validate the direction of rotation in self-tightening, speed and depth.
First, lathe machining, at a dimension + 0.03.
Then finish with a flat file + 800 grit paper, to the exact dimension with "0" clearance. This is to finish with fine lapping paste afterwards.
Then without disassembling the part, I transfer the chuck to the divider of my “13”
First open with a 20mm, 1mm thick disc cutter. As a reminder, I need 1.58 finished by 7 deep.
Then use a 1.5 end mill. Advance of 11mm/T and 2000rpm (maximum I can have)
At this moment, I have already cut 2mm deep and I assure you that I am watching like milk on the fire!!
Fortunately I only need two valves with an opening of 1/16"
LeZap